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// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under the BSD-style license found in the
// LICENSE file in the root directory of this source tree. An additional grant
// of patent rights can be found in the PATENTS file in the same directory.
package org.rocksdb;
/**
* This class provides a custom logger functionality
* in Java which wraps {@code RocksDB} logging facilities.
*
*
* Using this class RocksDB can log with common
* Java logging APIs like Log4j or Slf4j without keeping
* database logs in the filesystem.
*
* Performance
* There are certain performance penalties using a Java
* {@code Logger} implementation within production code.
*
*
*
* A log level can be set using {@link org.rocksdb.Options} or
* {@link Logger#setInfoLogLevel(InfoLogLevel)}. The set log level
* influences the underlying native code. Each log message is
* checked against the set log level and if the log level is more
* verbose as the set log level, native allocations will be made
* and data structures are allocated.
*
*
* Every log message which will be emitted by native code will
* trigger expensive native to Java transitions. So the preferred
* setting for production use is either
* {@link org.rocksdb.InfoLogLevel#ERROR_LEVEL} or
* {@link org.rocksdb.InfoLogLevel#FATAL_LEVEL}.
*
*/
public abstract class Logger extends AbstractImmutableNativeReference {
final long nativeHandle_;
/**
* AbstractLogger constructor.
*
* Important: the log level set within
* the {@link org.rocksdb.Options} instance will be used as
* maximum log level of RocksDB.
*
* @param options {@link org.rocksdb.Options} instance.
*/
public Logger(final Options options) {
super(true);
this.nativeHandle_ = createNewLoggerOptions(options.nativeHandle_);
}
/**
* AbstractLogger constructor.
*
* Important: the log level set within
* the {@link org.rocksdb.DBOptions} instance will be used
* as maximum log level of RocksDB.
*
* @param dboptions {@link org.rocksdb.DBOptions} instance.
*/
public Logger(final DBOptions dboptions) {
super(true);
this.nativeHandle_ = createNewLoggerDbOptions(dboptions.nativeHandle_);
}
/**
* Set {@link org.rocksdb.InfoLogLevel} to AbstractLogger.
*
* @param infoLogLevel {@link org.rocksdb.InfoLogLevel} instance.
*/
public void setInfoLogLevel(final InfoLogLevel infoLogLevel) {
setInfoLogLevel(nativeHandle_, infoLogLevel.getValue());
}
/**
* Return the loggers log level.
*
* @return {@link org.rocksdb.InfoLogLevel} instance.
*/
public InfoLogLevel infoLogLevel() {
return InfoLogLevel.getInfoLogLevel(
infoLogLevel(nativeHandle_));
}
protected abstract void log(InfoLogLevel infoLogLevel,
String logMsg);
/**
* Deletes underlying C++ slice pointer.
* Note that this function should be called only after all
* RocksDB instances referencing the slice are closed.
* Otherwise an undefined behavior will occur.
*/
@Override
protected void disposeInternal() {
disposeInternal(nativeHandle_);
}
protected native long createNewLoggerOptions(
long options);
protected native long createNewLoggerDbOptions(
long dbOptions);
protected native void setInfoLogLevel(long handle,
byte infoLogLevel);
protected native byte infoLogLevel(long handle);
private native void disposeInternal(final long handle);
}